Pressure-gage.



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PATENTED APR. 14, 1908.

-J. S; KENNEDY.

PRESSURE GAGE. APPLICATION 11.21) MAY4. 190B.

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No.'as4,592. PATENTED APR. 14,1908.

' J'. S.,KENNEDY. I PRESSURE GAGE.

APPLICATION FILED HAY4, 1906.

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PATENTED APR. 14,1908.

J. s. KENNEDY. PRESSURE GAGE. APPLICATION FILED MAY 4. 1906.

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W/ TtgE SSE S 110184592." Y PATENTED APR.14,1908.

J. s.v KENNEDY.

PRESSURE GAGE.

APPLICATION-FILED MAY 4. 1906.

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J! (4 I/ i ATTORNEY,

UNITED sTATEsr TENT OFFICE. Y

JAMES S. KENNEDY, OF NEW YORK, N. Y.

PRESSUBE-GAGE.

Application filed. May 4;, 1906.

To all 1127mm it may concern:

Be it known that I, JAMES S. KENNEDY, a citizen of the United. States ofAmerica, and a resident of the city, county, and State of New York, haveinvented certain new and useful. Improvements in Pressure-Gages, ofwhich the following is a specification.

This invention relates to a pressure gage for giving indications ofpressure at long d istances from the point of origin,-the pressure to bemeasured being that of gas or any other fluid or liquid. It may also beused for indicating variations in temperature.

The invention includes an electrical apparatus whereby pressurefluctuations can be electric ally transmitted automatically to anydistance.

In the present description I shall consider more particularly thefunction of the invention for use with gas pressure, because primarilythe invention is intended for use in conjunction with the distributionof gas for illuminating, heating and cooking uses, though this is onlyone of the numerous pur poses for which it may be successfully employed,and the fact that I describe this ap plication so minutely does not inany way signify th at its application is not very broad.

In. distributing gas to the consumers in a large city, the regulation ofthe pressure at which the gas is delivered to the consumer is a veryimportant matter. The pressure is commonly given to the gas by theweight of the gas-holders or tanks in which the gas is stored, and isregulated by suitable governors, and the pressure given to the gas atthe mint of supply must be varied at different hours of the day to meetthe variation in the consumption demanded, which variation is quiteconsiderable owing to the cl'iange in the quantity consumed at differenthours for cooking, lighting, and on cloudy days, or during shortabsences of the sun due to storm conditions which require artificiallight, etc, etc, the object had in view all the time by thosecontrolling the gas supply being to give the consumer a constant ornearly constant pressure' My invention enables this to be attained.because its mechanism constantly advises the attendant in charge of thegovem or at the h older or initial point, regarding what the pressure ofthe gas is at the distant point where consumption is taking place, whichin a city like New York is often two miles ormore from the initialpoint, so that said attendant by properly regulating the Specificationof Letters Patent.

Patented April 14, 1908.

Serial No. 315,256.

governor may have complete control of the pressure at the distant pointand keep the same constant or nearly constant at all times and under allconditions.

It has been found in experience that a long distance pressure gage fordoing the kind of work to be performed by my present inven tion ought tohave the following characteristics: first, simplicity of apparatus sothat the parts may be as few in number as possible and not complex;second, system to be automatic so that every change in pressure may bepromptly indicated in a suitable manner; third, a single electricalcircuit; fourth, the measurements of pressure to be indicated by visualmeans or audible means,

or both; fifth, the two ends of the apparatus, 71. e., the point ofpressure origin and the point whose pressure is being noted to havetheir mechanisms operating always in unison, even to the extent thatshould the main circuit or battery be rendered inoperative, themechanisms will upon arestoration of normal conditions immediatelyindicate the existing pressure no matter what changes of pressure mayhave intervened while the machine was out of order; sixth, means forverifying the accuracy of the readings or indications at the.

supplypoint so as to absolutely safe-guard against any mistake andobviate the necessity for frequent comparisons by telephone, messenger,or otherwise; seventh, some kind of audible notification when a changeof pressure takes place, so that the attention of the attendant mayimmediately be attracted; eighth, some means for automaticallyindicating that the device is out of order whenever any contingencyoccurs like the breaking of a conductor to render the machine temorarily inoperative; ninth, when clockwor is employed to drive themachine-or a part of it, it should require winding not oftener than oncea day and referably not oftener than once in several days; tenth,absence of reversals of polarity and changes of current strengthrequiring polarized-relays, local batterles, etc.

With these and other objects in view, my invention consists essentiallyin the con struction, arrangement and combination of parts and in varousdetails and peculiarities thereof substantially as will behereinafterdescribed and then-more fully pointed out in the claims.

In accom anying drawing illustrating my invention: igu're 1 is a sideelevation of the transmitting mechanism. Fig. 2 is an en largedlongitudinal sectional view of the same. Fig. 3 is a top plan view. Fig.4 is an enlarged end elevation. Fig. 5 is a diagrammatic view of thetransmitter mechanism, the receiver mechanism and the elecnumbersthroughout the different figures of the drawing.

The invention comprises essentially a trans- Initting mechanism which Iterm a transmitter, which is situated at some point distant from the gassupply, that is to say, at

the point of gas consumption; and a receiver or-indicator mechanismwhich in the present description of the invention I term a receiver,which is located in proximity to the gas su )ply; and a main lineconsisting of an e ectrical conductor between the re ceiver and thetransmitter, which conductor may be a metallic circuit, or it may have areturn through the earth. The transmitter is provided with a dial,though this is not es sential; the receiver is also provided with adial; and both dials have hands or pointers the movements of which aresynchronous. The transmitter dial when one is used has one moregraduation than the receiver dial, so that there may be one point on thereceiver dial equal to two points on "the transmitter dial, to provide apause in the move ment of the receiver hand. As one example, thetransmitter dial has sixteen graduations and the receiver fifteen, andin each case the workings preferably run from 15 to 29, in-

stead of from zero to 15.

In Fig. 5 we see the transmitter dial 19 having a hand 18, and thereceiver dial 78 havin a hand 77. An electric circuit is establishedbetween the receiver and transmitter. That portion of the circuitbelonging to the receiver is shown in dotted lines at manner toaccommodate therewith the various mechanical parts, one example of thesame being indicated in Figs. 1 and 2, Where it is seen to have asubstantially rectangular shape, and among various parts to have twovertical sides to permit the journaling therein of certain arallel horizontal shafts. 3 denotes one 0 these shafts supported at each end in thesides of the frame 1 and carrying a gear wheel 2, a ratchet-wheel 5having a pawl 6 which is pressed into the teeth of the ratchet by meansof a spring 6, and also a drum 4 around which is wound a cord 86attached to a weight 87 (see Fig. 5), the function of the weight beingto revolve the drum, the shaft 3, and the gear wheel 2 whenever thecondition of certain other parts permits, as will be hereinafter morefully' explained. Parallel to the shaft 3 and likewise journaled in thesides of frame 1 is a shaft 7. On it is a pinion 8 which is engaged bythe gear-wheel 2. Shaft 7 also carries, preferably at the end oppositewhere the pinion 8 is located, a gear wheel 9. Also parallel to theshafts 3 and 7 is a third shaft 11 likewise journaled in the sides ofthe frame 1, and carrying a pinion 10 which is in mesh with the teeth ofthe gear wheel 9. Gear wheel 9 on shaft 7 has eight times as many teethas the pinion 10 on shaft 1], and consequently the shaft 11 will revolveeight times while the shaft 7 is revolving once. The gear wheel 2 inaddition to engaging the teeth of the pinion 8 engages also the teeth ofthe pinion 12 on the end of the short shaft 13, see Figs. 2 and 4. Saidpinion 12 has one-half as many teeth as the pinion 8, and hence theshaft 13 will revolve twice while the shaft 7 is revolving once and,carrying this eX lanation further, it will be seen that the s iaft 13will revolve twice while the shaft 11 is revolving eight times, or oncein four revolutions of shaft 11. Also, the shaft 7 carries a hand orpointer 18 which moves over a small raduated circle 19 held stationaryby suitab e means on the side of frame 1. See Fig. 1. This dial 19 isprovided with sixteen graduation marks which divide it into 16 equaldivisions, and, although this dial is not necessary to the correctoperation of the machine, provides a handy and convenient means forinspecting or testing the o eration. The division points are preferab ynumbered from 15 to 29 except that the number 15 applies to two of them.

On the shaft 11 is mounted an escapement wheel 14, and contiguousthereto is arranged an escapement 15 having a pendulum 16 and used forthe purpose of checking the movement of the shaft 11 when the latter isset free. Also, on shaft 11 is a cam 17 having two high and twolow'points, making it in effect a double cam. Above this cam is aT-shaped latch 20 which swings on a pivot 21 supported on somestationary part 22 of the main frame. The T-shaped end of this latch isnormally given a downward tendency by means of a spiral spring 23 whichis fastened to the latch at a short distance from its pivot 21, and atthe other end is fastened to some stationary art of the frame. The latch20 rises and fal s under the action of the cam 17 revolving beneath it,and hence is made to rise and fall twice in each revolution of the shaft11 on which cam 17 is mounted The T-shaped end of the latch 20 is alsoprovided with two pins, one of which, 24, projects horizontally on oneside near the upper end of the T-bar, while the other, 25, projectshorizontally on the other side near the lower end of the T-bar.

In the upper portion of the main frame 1 above the shaft 11, is anelectro-magnet 26 having an armature 27 provided with a lever 28 pivotedat 29 to the main frame, and carrying at its lower end a pin 30, whichat times projects beneath the latch pin 24 and hangs up the latch byallowing said pin to rest thereon. A spring 31, fastened to the lever28, pulls the armature 27 away from magnet 26 whenthe latter isdemagnetized, the result of which pulling away withdraws the pin 30 frombeneath the latch'pin 24. This magnet 26 is a control magnet,controlling through its armature and the latch 20 the rotation of shaft11.

On the shaft 11, preferably adjoining cam 17 is a double crank arm 32,provided at each end with a horizontally projecting pin 33. When thelatch 20 is hung up so that its in 24 rests on the armature pin 30, thelower atch pin 25 will bear against one of the crank pins 33, and thusthe crank will be locked and the shaft 11 prevented from revolving. Theshaft 11 is always given a tendency to revolve by the action of theweight 87 below the drum 4, and the inter-action of the gears resultingtherefrom, but it is manifest that as long as the latch is suspended onthe electro-magnet armature lever 28, a condition which obtains so longas the control magnet is energized, the shaft 11 cannot move but must 0necessity remain stationary, the path of the crank-pin 33 being. blockedby the latch-pin 25; but the moment the magnet 26 ceases to attract itsarmature 27, the spring 31 will withdraw the oin 30 from beneath the pin24, which will cause the T- shaped end of latch 20 to fall, therebycausing the latch-pin 25 to move out of the way of crankin 33, whereforeit will result that there being no longer any obstacle to the movementof the crank 32, and the shaft 11 being under the influence of theweight, saidinoperative, the latch 20 will simply rise and fall underthe influence of the double cam 17, the pins 33 on the crank clearingeach time the pin 25 on the latch, and the shaft 11 be ing: allowed tocontinue to revolve until the magnet 26 is again energized and the latchsuspended in its upper position in consequence. shaft 11 to revolve inthe manner just explained,-while the magnet 26 is inoperative, thepositions of the double cam 17 and the double crank arm 32 on the shaft11 with respect to each other, must be such that the T- shaped end ofthe latch 20, after leaving the high points of the periphery of cam 17will have room to drop and allow the pin 25 to pass under and clear thecrank pins 33.

The construction and relative location and adjustment of the variousparts will effec tually prevent the pin 24 from catching under the pin30 at any time, as .will be clearly understood from the following verybrief eX planation. Pin 24 obviously moves u and down in correspondencewith theoscil ation of the latch 20. Its downward motion is the T-shapedend of latch 20 with cam 17 on which it rests. Pin 30 is so located onthe armature lever 28 that it cannot possibly get over the pin 24, evenwhen pin 24 is at the lowest point of its drop. The nearest it couldever come to doing this would be to strike squarely against the pin 24.Pin 30 is, however, preferably sharpened somewhat 'at its outer end sothat should it happen ever to strike against the pin 24 (which is by nomeans likely) it will meet the rounded or cylindrical surface of saidpin 24, and this will help the pin 30 to slide under and lift pin 24.Or, to give another reason why there is no possibility of the pin 24catching under the pin 30 when the magnet 26 is energized and the latch20 oscillated, I may say that the cam 17 is so located on the shaft 11with relation to the cam 41 that the magnet 26 can only be energizedduring certain positions in the oscillation of the latch 20. Con.-sidering this further, cam 17 causes latch 20 to move up and down, andcam 41 opens and closes the electric circuit at certain parts of therevolution of shaft 11. Referring to Fig. 5, it will be seen that whenpin 24 is approaching its highest position, the cam 41 will close themain circuit by allowing s rings 42 and 43 to come together, and wilkeep It is clear that in order to allow the limited by the contact ofthe lower part of said main circuit closed during a quarter of arevolution. of shaft 11, or until'after the pin 20 has reached itshighest position and descends again. Now at the moment the circuit isclosed, if magnet 26 is operative, it instantly attracts its armatureand throws the pin 30 forward; but at that moment pin 24 is sufficientlyhigh to allow pin 30 to slide under it. Furthermore, the speed of pin 30in making its movement forward is much greater than the movement of thepin 24 in going up or down, since the attraction of the magnet 26 causesits armature to move suddenly and quickly, throwing pin 30 for wardunder the pin 24 before the latter can drop too low.

In the lower part of the main frame a suit able distance below the latch20, is an electro-magnet having an armature 36 provided with a lever 37hung pivotally at 38 on some part of the main frame, said lever 37 beingprovided near its upper end with. a hori! zontal pin 39, which isadapted to engage with a horizontal pin 34 on the end of the latch. 20,by projecting over said pin at certain times. Said pin 39 operates inconjunction with the pin 34 in a manner quite similar to the operationof the armature pin 30 in conjunction with the latch pin 24, and iseffectual in looking the latch 20 in a certain position by advancing andstaying over the pin 34, when the magnet 35 doesnot attract its armature36, for when there is no such attraction, a spring 40 which. is fastenedto the armature lever 37, and also to some sta tionary part of theframe, operates to draw over the lever 37, and hence moves pin into aposition above the pin Ordinarily when the machine is at rest the magnetis energized and hence the armature 36 is attracted thereto, butmanifestly during the operation of themacl'iine this magnet 35, being inthe main electric circuit, is subject to being frequently demagnetizedand then energized again, and so it is to be observed of these thingshappens, the armature 36 will fall loose from the electro-magnet 35under the power of the spring 40, and this will cause the pin 39 to slipover the pin 34, cansing the latch 20 to be locked, ,after whichobviously the shaft 1]. cannot be rotated but must remain stationary solong as the latch 20'is locked. Hence it is evident that the shaft 1.].is rendered inoperative by the breaking of the main line, or thedestruction or ence on the part with which they come in contact for anappreciable length of time.

The lengths of each of the high portions a a and also of each of the lowportions 7) b are equal to eachother, and each equal to onequarter ofthe total periphery of the cam 41.. In convenient proximity to the cam41 are two contact springs and 43 securely fastened to the insulatedsupport 44. These springs 42 and 43 are part of the main electricalcircuit. They are provided, respectively, with platinum points 45 and 46which are normally in contact with each other when the niiachii'ie is atrest, and the spring 42, which projects nearer to the cam 41 than spring43, is preferably provided with a small knob or its equivalent 47, whichis wiped by each of the high parts a a of cam 41. during the revolutionof the latter, the result of this wiping contact being to deflect thespring 42 sufficiently to separate the pins 45 and 46 from each other,and thus make a break in the main circuit. Accordingly, it is clearlyseen that when the shaft 11 is rotating, the main electrical circuitwill be opened and closed in each revolution of this shaft by thebreaking of the circuit caused each time the contact springs 42 and 43are spread apart, and. as the circuit breaks twice in each revolution ofthe shaft 11, it will be broken sixteen times in each revolution of theshaft 7 carrying the pointer 13, when it is remembered that the shaft 11revolves eight times during one revolution of the shaft 7.

Returning in my (.lescription. to the shaft 7, it is provid ed with arigid crank arm 48 having an arc-shaped outer end, the arc loeingconcentric with the axis of revolution of shaft 7, or the outer end ofthe crank 48' beingT shaped with. a curved edge. This arm 48 coincidesin position with the pointer 18, that is to say, it projects in the samedirection, but being on the "opposite side of the dial 19, and henceduring the progress of the pointer 18 over the face of the dial 19, thecrank 48 follows a correspomling movement behind the dial. In convenientproximity to the arm 43 as it rotates about its center of movement, aretwo ,flat springs 49 and 50 supported by attachment to an insulatedblock 51, carried by the mainframe. These springs 49 and 50 areconnected by suitable wires 0 and d to the springs 42 and 43, to whichthey are quite similar in construction and. arrangement. Springs 49 and50 are preferably furnished with suitable platinum or other contactpoints 52 which are normally out of contact with each other, and spring49 is preferably provided with a small knob 53 which is wiped by theouter end of the arm 48, whenever said arm reaches that point in itsrevolution where it stands ver tical and where the pointer 18 points tothe lowest number in the scale 19, which in the present example is thenumber 15, or rather the space between the graduations 15 and the onenext preceding it. The result of the arm. 48 wiping the spring 49momentarily is to cause the contacts 52 on these springs49 and. to meet,and. thus close the circuit which is normally open at this point. Thearm. 48 is so situated on shaft 7, and the 02111141 is so situated onshaft 1.1, that a proper timing in the operation of these parts willoccur, so that the'closing of the circuit through the bringing of thesprings 49 and 50 together by the action'of the arm 48, when the pointeris at a predetermined point in its movement around the circle, will takeplace simultaneously with one of the openingsv or breakings of thecircuit through the separation of the springs 42 and. 43 from each otherin consequence of-the action of cam 41. It is to be remembered, however,that the closing of the circuit by bringing the springs 49 and 50together, occurs only once in the revolution of the shaft 7, andconsequently in the rotation of the crank arm 48. The effect of thisoperation of closing the circuit by springs 49 and 50, which I havestated are electrically connected with the springs 42 and 43, is toneutralize or destroy one of the openings of the electrical circuitwhich takes place when the springs 42 and 43 are separated,so thatduring each series of eight resolutions of the shaft 11, whichordinarily would mean sixteen breakings of the electrical circuit, onebreaking of the circuit is lost, for it does not take place at themoment when the arm 48 wipes against the knob 53 on the.spring 49.Therefore, when shaft 7 makes one complete revolution, the electricalcircuit would ordinarily be opened and closed sixteen times,

because shaft 11 revolves eight times to one revolution of shaft 7 andshaft 11 opens and closes the circuit twice in eachrevolution, but theneutralizing of one opening of the circuit, as just explained, causesthe circuit to be opened and closed fifteen times instead ofsixteentimes, and the interval that elapses between the opening immediatelypreceding the con-tact of arm 43 with spring 49, and the opening whichoccurs immediately after such contact is twice as long as the intervalbetween the opening and closing of the circuit at other times. Thiscauses a pause, as I term it, which is very noticeable to the attendantlooking at the receiver dial of the machine and which. enables theoperator to perceive whether or not the machine is work as indicated inFig. 3.

7 drives a pinion 12 on shaft 13, which pinion 12 has only half as manyteeth as the pinion 8, so that while the shaft 7 makes one revolution,the shaft 13 makestwo revolutions,- and consequently remembering thatthe ratio of revolutions between shaft 7 and shaft- 11 is l to 8, whenthe shaft 13 revolves once, shaft 11 will make four revolutions. Thisshaft 13 is suitably supported in the frame 1 At one side of the frame 1there is provided a lateral extension 54 for the accommodation of shaft13 and certain parts which I am now about to describe. On the end of theshaft 13 opposite to the pinion 12 is a bevel gear wheel 55 whichengages two bevel pinions 56 and 57 carried by a shaft 58 which is atright-angles to and securely fastened to a shaft 59 which is in linewith the shaft 13, and one end of which is supported in a bearing in thecenter- *gear 61 engages with the two bevel pinions 56 and 57 in likemanner as does the bevel gear 55, though opposite thereto. Thisarrangement of gears provides a differential gear mechanism and enablesthe shaft 59 to be driven either separately or conjointly by See Fig. 3.Anothermeans of the gear wheels 12 and 63, as Wlll be hereinafter morefully explained. In the arrangement described and in order that thebevel gears may properly mesh into each other, those gears opposite toeach other must have the same number of teeth, that is to say, gearwheel 55 has the same number of teeth as gear wheel 61, and pinion56 hasthe same number of teeth as pinion 57.

The gear wheel 63 is engaged by a vertical rack bar 64, as indicated inFig. 1, and more fully shown in Fig. 9. This rack bar 64 is connected toa rod 100, which extends into a suitable tank 101, wherein it is"connected to a float 102 or other suitable similar device, which isacted upon by the gas pressure com ing through the pipe 103 from thedistributing mains, or other source, so that as the pressure of thegasor other fluid rises or falls, the rack bar 64, which will likewiserise or fall, will rotate the gear wheel 63 backward or forward, whichin turn will drive the bevel gear wheel 61 and the difierentialmechanism. Though. it is unnecessary to describe the tank here, inasmuchas its construction may vary widely, and whatsoever might be offeredhere would be given simply by way-0f thus close the circuit.

illustration and suggestion, it is not amiss to state that as shown inFig. 9, this tank may consist of the water-containing receptacle 101 inwhich is .the small gas holder 102 mounted in suitable guides and havinglateral anti-friction rollers 10 1 which play up and down 011 the insidesurface of the receptacle 101. Inside of the gas holder 102 is adisplacement chamber 105. The gas pipe 103 running from the. mains orsomeother source, communicates, as shown, with the annular s ace betweenthe holder 102 and the displacement chamber 105. The holder rises andfalls directly proportionately to the pressure, and, as stated,reciprocates the rack bar 64 so that the pinion 63 may be actuated.

On top of the tank 101 are preferably placed small rollers, 106, on eachside of the rod 100 to facilitate the up and down movement of thelatter.

On the shaft 59 there is also a disk 65, insulated on shaft 59, whichdisk has a notch 66 at one point in its periphery. The disk 65 revolvesbelow a horizontal contact spring 67, one end of which is made fastwhile the other plays freely beneath and in relation to a contact screw68, see Fig. 1. a small rojection consisting preferably of a littleroller 69 which rides on the periphery of the disk 65, and normally isat rest in the When the roller is thus in the notch 66, the end of thespring will be away from the screw 68 and the circuit at this pointwill. be open. When, however, the disk 65 revolves more or less in onedirection or the other, the roller will be lifted up out of the notch,which will cause the end of the spring 67 to make contact with the screw68, and The notch 66 is of such a length that during one revolution. ofthe disk 65, the circuit between spring 67 and screw 68 will be closedduring "fifteen-sixteenths of this revolution, and open duringone-sixteenth v art of the revolution.

From what have already said, it must be evident that owing to thepeculiar characteristics of a differential gear mechanism like thatherein described and shown, the gear wheel 12 or the gear wheel 63 mustmake two revolutions to revolve the disk 65 once, it being rememberedthat the gear 55 has the same number of teeth as the gear 61, and thepinion 56 the same number of teeth as the pinion 57. The diameter of thegear wheel 63 is such that the rack 64 which engages the teeth of thisgear must rise eight units in pressure to cause gear wheel 63 to makeone revolution, and therefore it must rise sixteen units in pressure tocause the disk 65 to complete a single revolution; and furthermore theshaft 7 must revolve once to carry the disk 65 around once, provided therack 64 and the gear wheel 63 remain stationary. If, however, while theshaft 7 is making one revolution, or a part of a revolution, the rack 64Spring 67 has should move up or down, (that is to say, if the pressureshould change while the machine .is in motion) then the shaft 7 willmove a understood that a point pressure or one unit of movement up ordown by the rack is represented by a half-revolution of the shaft 11 byone-sixteenth revolution of shaft 7, and by one opening and closing ofthe circuit at springs 42 and 43.

The pinion 12, shaft 13 and gear wheel 55 may be considered as formingtogether one member of the differential gear mechanism, inasmuch asthese three parts are rigid with respect to each other, and must moveconjointly. The gear wheel 61, gear wheel 63 and hub 62 togetherconstitute a second member, since gear wheel 63 is mounted upon ordriven tightly on to the hub of gear wheel 61, and they revolve looselyon the shaft 59. The gear wheel 56, gear wheel 57 and shafts 58 and 59together constitute a third member, inasmuch as they operate conjointly.Gear wheels 56 and 57 revolve freely on the shaft 58 and they mesh asstated into the gears 55 and 61. The shaft 58 is at rightangles to shaft59 and is rigidly connected thereto, so that shafts 58 and 59 move inunison with this exception, that while shaft 59 revolves shaft 58 movesaround in a plane at rigltit-angles to the of rotation of shaft 59.Shaft 59 has one end resting in the center of the gear wheel 55, asshown in Fig, 8, so that gear wheel 55 serves in part a bearing for anda support for one end of the shaft 59. Now, if we assume the secondmember just specified, consisting of gear wheels 61. and 63 and hub 62,tobe stationary, it must clearly follow that if the shaft 13 re volves,it will cause shaft 59 to revolve in the same direction, by reason ofthe gear wheel 55 causing the gear wheels 56 and 57 to revolve on theshaft 58. As the gear wheel 61 is now assumed to be stationary, the gearwheels 56 and 57 must travel around on the periphery of the gear wheel61, carrying the shaft 58 around with them, that is to say, causing theshaft 59 to rotate in the same direction as the shaft 13. In this mannerthe gear wheel or pinion 12 can drive the shaft 59. Similarly, if weassume the first member just specified, consisting of pinion 12, shaft13 and gear wheel 55, to be stationary, and the second member,consisting of the gear wheels 61 and 63 and the hub 62, to be movable,it will be seen for the reasons just stated that if gear wheels 61 and63 are revolved, they will cause the shaft 59 to revolve in the samedirection. Now, if both the shaft 13 and the gear wheel 63 are rotatedat the same time, either in the same or Opposite directions, the effectwhich they eX ert on shaft 59 will be a resultant effect of themotionsimparted to it by the shaft 13 and the gear 63, that is to say,shaft 59 will either remain stationary or will rotate forward, or willrotate backward, in consequence with the ,resultant effect of therotations of the shaft 13and the gear wheel 63. If the shaft 13 and thegear wheel 63 are rotated in opposite directions at the same rate ofspeed, the shaft 59 will remain stationary because the effects impartedto it by shaft 13 and gear wheel 63 are equal and opposite, andneutralize each other, and nothing therefore happens except that thegear wheels 56 and 57 revolve on the shaft 58. If the shaft 1.3 and thegear wheel 63 rotate in opposite directions, but at different speeds,then shaft 59 will rotate in the direction of the one moving faster, andat a speed of or to an extent which is equal to half the difference .ofthe speed of shaft 13 and gear wheel 63. For example, if in a given timeshaft 13 makes two revolutions in a clockwise direction and gear wheel63 makes one revolution in the opposite direction, the shaft 59 willmake a half revolution in a clockwise direction. If shaft 13 and gearwheel 63 move at the same speed in the same direction, the whole systemwill rotate as one, that is to say, shaft 59 will rotate in the samedirection at the same speed, and in this case the gear wheels 56 and 57will not revolve on the shaft 58. If shaft 13 and gear wheel 63 move atdifferent speeds in the same direction, the shaft 59 will rotate in thesame direction at a speed which is equal to half the sum of the speedsof shaft 13 and gear wheel 63'. For example, if in a given time shaft 13makes two revolutions in a clockwise direction, and gear Wheel 63 makesone revolution in the same direction, then shaft 59 will rotate one anda half revolutions in a clockwise direction. Assigning positive andnegative values for forward or backward -motion, it may be stated thatthe motion of shaft 59 is equal to half the sum of the motions of shaft13 and gear wheel 63. The relative number of teeth in the gear wheels 56and 57 and 55 and 61 is of no consequence, and does not enter into themotions which I have just described. The only bearing which such arelation has is in the number of revolutions which the gear wheels 56and 57 make on the shaft 58, which is obviously immaterial for therequirements of this mechanism. Preferably the sizes or the number ofteeth in the gears 56 and 57 are small because they are thereforelighter and cause less friction. Hence it will be understood from thisanalysis that the shaft 59 may properly be said to be driven eitherseparately or conjointly by means of the gear Wheels 12 and 63.

Proceeding now to briefly describe the receiver and referring to Fig. 5,it will be seen that it consists of an electro-magnet 7O having anarmature 71 to which is attached an armature lever 72 pivoted at 73 andfuruations on dial 78 are preferably numbered from 15 to 29. A spring 79is connected to a stationary part of the frame and to the armature lever72 below its pivot 73, and has the function of drawing the armature 71away from the electro-magnet 70. 80 de notes a test key on a spring 81.which normally is in contact with screw 82. pressing the key 80 the mainline can be broken or opened at this point.) If the electro-magnetceases to attract the arma ture 71 by reason of the breaking of thecircuit, either at the test key or by the operation of the transmittermechanism, said armature 71 will drop away from the magnet 70 and thiswill cause the forked detent 74 to drive one of its teeth into theratchet 75 while the other is withdrawn, and this will throw the ratchetwheel 75 forward half a tooth, and hence if the circuit of theelectromagnet 70 is broken once, that is to say, is opened and closedonce, the pointer 77 is driven forward one-fifteenth of a revolution.

I will now'begin to describe the operation, first assuming that the hand18 on the transmitter dial 19 is in unison with the hand 77 on thereceiver dial 78, that is to say, it points in each instance to a numberrepresenting the same pressure, and this is the pressure in the tank inconnection with which the rack bar 64 operates. Under normal conditions,the transmitter is at rest with the roller 69 on the spring 67 lyingwithin the notch 66 in the disk 65, as shown in Fig. 5.

Suppose now that the pressure in the transmitter tank, which is thepressure in the distant distributing main in city service, rises oneunit, say, from 25 to 26. This will cause the rack 64 to lift and thegear 63 to make one-eighth of a revolution, which movement of the gear63 will impart a one-sixteenth revolution to the disk 65 which will,therefore, shift from the position shown in Fig. 5 to that shown in Fig.6. In so doing the disk 65 lifts the spring 67 and brings it intocontact with the screw 68 and thereby short circuits the electro-magnet26 without opening the main line. Immediately the armature 27 drops awayfrom the magnet 26 under the tension of the spring 31, acting on thelever 28, and thus the pin 30 is withdrawn from the top pin 24 on thelatch 20, and the T- shaped end of the latch allowed to fall, which (Bydetakes away the latch pin 25 from its obstructive position in front ofthe crank pin and gives the shaft 1.1 an opportunity to rotate, which itreadily does. The instant, however, that the shaft 11 starts to move,the cam 41 opens the springs 42 and 43, thus temporarily breaking themain line, and then closes them together again. This opening and closingof the main line circuit does not affeet the magnet 26, for it isalready short circuited at spring 67 and screw 68, but it does cause thearmature 36 of magnet 35 to recede from the magnet and immediatelyreturn to it again, causing the pin 39 to move into the path of pin 34,but this is so timed in consequence of the relative positions of pins 39and 34 that pin 34 dodges or clears pin 39 without hanging up the latch20; The opening and closing of the main line circuit also demagnetizesmagnet 70, and then immediately magnetizes it'again, thus causing thearmature 71 to recede from and then return to said magnet, the result ofwhich is to cause the forked detent 74 to drive the ratchet wheel 75around for the distance of one tooth, so that the pointer 7 7 movesalong one point on the dial 78, which would, for example,

bring it up tothe figure 26 on the dial. Before the shaft 11 hascompleted one-half of a revo- .lution, however, the large gear wheel 2which engages with the pinion 12 on shaft 13, will by actuating saidpinon 12, cause through the ilifl'erential gear device consisting ofbevel gears 55 and 61. and bevel pinions 56 and 57, an action to takeplace upon the shaft 59 in a direction reverse of that caused by thepreviously-mentioned movement of gear wheel 63, so that the disk willrevolve back to its normal. position which is shown in Fi 5, wl'icre theroller 69 lies loosely in the notch 66. This, of course, stops the shortcircuit around magnet 26 by taking spring .67 out of contact with screw.68 and allows the magnet 26 to be magnetized again as soon as shaft 1.1moves cam 41 far enough ,to permit the closing together ofthe springs 42and 43, for then the magnet 26 instantly attracts ari'nature 27, causingarmature pin 30 to pass under latch pin 24 and give support to the latch20, so that the shaft 11 will stop after it has completed one-half of arevolution. From this it is manifest that a rise in pressure of one unitfrom the twenty-fifth graduation to the twenty-sixth graduation has beenproperly transmitted by the transmitting mechanism. to the receivermechanism, and that the hand of the receiver 77 has indicated to theattendant at that point the change in pressure at the distant station,because the hand 77 has moved up on the receiver dial from thetwenty-fifth graduation to the twenty-sixth graduation, while also thepointer 18 on the transmitter dial 19 has moved. one-sixteenth of arevolution and passed from the twentyfifth graduation to thetwenty-sixthgraduation. In this connection, an important thing 18 to benoticed, viz: that the rack 64 of pressure either up or down, and isthefirst elei'nent to be disturbed thereby, is capable of driving thedisk 65 in one direction or in the other, in one direction as shown inFig. 6, in anotliier direction as shown in Fig. 7, be, cause the rackrotates the gear 63 either backward or forward, but the pinion 12 canonly drive the disk 65 in one direction which is termed clockwise, beingin the same direction as the :i'novei'nent of the hands of a clock. ofcourse 1 do not mean to restrict myself to having the disk 65 alwaysmoved by pinion 12 in a clockwise direction, but what 1 do mean to sayis, that it is always moved in the same direction when acted on by thepinion 12, and though the. machine may be organized so that thismovement will be contraclockwise, yet the reorgai'iization of themovsiderable to permit this.

Continuii'ig the explanation, I will now assume that the pressure in thetank at the traiiisi'nitter end of the apparatus where the rack 64 islocated, drops a unit, that is to say, goes down fI'OIl'n. 26 to 25. Therack 64 will consequently drop a point and this will through theconnection with the gear 63 re Fig. 7. This cl'novement lifts the spring67 into contact with the screw 68, and a short circuit is establisl'iedaround the electro-magnet 26 as ii'idicated in Fig. 5, which as beforeexplained in the of an increase of pressure will unlock the shaft 11 andallow it to revolve. Also as before explained, the pinion 12 on theshaft 13 will be set in motion, and through the action of thedifferential gear mechanism, the disk 65 will be rotated for wardly inthe direction. of the arrow shown in 'Fig. 7 (not backwardly) until thedisk has completed the revolution and the notch 66 again receives theroller 69, as shown in Fig. 5. All the while during this completerevolution, the spring 67 is kept in contact with the screw 63, and themagnet 26 is short-circuited. Of course, as soon the roller 69 againdrops into the notch 66 at the end of the revolution of the disk, themagnet 26 is again magnetized at the next closing of the springs 42 and43, resulting in the stopping again of the shaft 11. During all thistime the disk 65 has moved tl'irough fifteen-sixteenths of a revolution,it being remembered that the notch 66 is one-sixteenth of a revolutionand the shaft 11 has revolved seven and onehalf times, and the contactsprings 42 and 43 have been opened fifteen times, although the effect ofone of these openings has been canceled by the closing of the springs 49and 50, so that the main line circuit has really only I been opened.fourteen times. These fourteen wl'iich first sustains the influence of achange,

ing parts in this case would have to be coni volve the disk 65 into theposition shown in preferably a forward direction, or what is 'which willclose the circuit. again.

openings or breakings of the main line circuit a pointer, as 18, andwhich position of shaft 7 have caused the mechanism of the receiver tocorrespondingly operate the ratchet wheel 75, inasmuch as fourteenoperations have been given to the magnet 70, and to the forked detent 74which has caused the pointer 77 to move around through. fourteendivisions, thus bringing it to the twenty-fifth indication on thegraduated circle. At the time when the springs 49 and 50 are closed, theverification pause occurs in the movement of the receiver pointer, whenit is at the graduation 15 on the receiver dial.

If it shouldhappen that while the transmitter is operating, and thecircuit opening and closing fourteen times in the manner I have just eXlained, the pressure in the tank should rise or fall, this rise or fallis communicated to the disk 65 through rack 64 and gear 63, and

this eitherdelays or hastens the disk 65 in its revolution, which hasthe effect of adding or subtracting one or more revolutions of the shaft11, the resultant effect being that the necessary number of impulses aresent to cause the receiver at the time when it stops moving to indicateaccurately .the pressure which is being registered at the transmitter.

In case the attendant at the receiver wishes to verify the accuracy ofthe indication which is being made at any certain time by the pointer77, in other words, if he wishes to test the reliability of the machine,all he has to do is to open the main circuit for a-mo ment by depressingthe key 80, thereby removing the spring 81 fromthe contact screw 82, andthen release the key--80 and let the spring 81 again contact with thescrew 82 Immediately upon the breaking of the circuit, the

armature 27 will be removed from the electro-magnet 26, and consequentlythe shaft 11 will begin to revolve, which 'willcause the disk 65 tobegin to move into the position shown in Fig. 7, where the roller 69 isremoved from the notch66 and the disk being startedin the direction ofclock hands must .pointer 77 around to the same point where it wasbefore. The verification pause was also given at the time when thesprings 49 and. 50 were brought together simultaneously with one of theopenings of the circuit at 42 and 43, a thing which-occurred at themoment that the hand 77 was on the zero .point or the low- 1 estgraduation ofthescale. Thisproves that the pointer 77 is in unison withthe shaft 7,

the position of which is usually indicated by is in unison at all timeswith the pressure in the tank. Thus it will be understood that thecorrectness of the receiver indications.

When themain line is broken, or the battery or. batteries arefor anyreason .putout of commission, ,the electromagnet 26 belonging to thetransmitter, will cease ,to attract its armature 27.and this will cause.pin 30 to withdrawfrom under the pin 24, thus allowing the T,shaped endof latch 20 to descend andunlock shaft 11, allowing it to start inmotion as previously explained. However, the breaking of the circuit orremoval of batterypower has also affectedthe magnet, 35, causingit torelease its armature 36. This causes pin 39 to advance towards pin 34.As the armatures 27 and 36 are released simultaneously, it is clear thatpin 6 30 starts to withdraw from under pin 24 .at the same instant thatpin39 advances towards pin 34. The length of pin 30 and the distancebetween pins 39 and 34 are so adjusted that pin 30 withdraws its supportfrom pin 24 before pin 39 has advanced overpin 34. This allows pin 25 topass below pin 33 and unlock the shaft 11 before pin 39 has a chance toholdlatch 20 by advancing over pin 34. The shaft in starting, causes theT-shaped end of latch 20 to rise again almost immediately by reason ofthe shape of cam 17, and bearing in mind the shape of this cam 17 itisclear that the vmotion of pin 34 after the circuit has been broken is torise instantly, then gradually to, desoend,-and then rise again by asudden and quick motion. In rising thus, it strikes against pin 39 whichby this time'has advanced. across its path and remains'there. Thisprevents pin 34 from rising any higher and thus hangs up latch 20,causing pin 25 to obstruct the path of the next pin 33, stopping andlocking the shaft 11 after it has made but one-half revolution, and thisosition of the parts will obtain and remain as ong as the circuit-isbroken or battery power removed. At the same time, the receiver magnet70 releases its armature 71 and does notattract it again while the lineis broken,

a condition which moves the ratchet wheel 75 forward the distance ofhalf a tooth and not the whole distance, and hence causes the pointer 77to assume a position intermediate between two consecutive divisions.Therefore it is evident that whenever the receiverpointer instead ofpointing directly to one o' the scale numbers is between two of thedivisions, there is something wrong. If the attendant upon glancing atthereceiver dial sees the pointer at any time in .this mid-position, itis evident to him that the apparatus is not working, and ste s should bepromptly taken to'ascertain tie other desired manner.

"transmitter cause. Upon testing with the test-key 80, the attendantwould find that the hand does not move as itusually does when such atest is made. If the pressure at the transmitter changes while the lineor the battery is out of commission, the rack 64 will be moved up anddown by the pressure as usual, and the gear 63 will as-usual move thedisk forward or backward lifting the spring above the peripheral notch,and causing the customary short-circuit of the magnet 26, but as soon asthe line or battery isrestored the mechanism will immediately begin tooperate, and the disk must of necessity be carried back into its normalposition, where its notch receives the roller 69, whereby the shaft 11is revolved around the necessary number of times to bring the receiverpointer 77 so that it will be in unison with the, pressure existing atthe transmitter and indicated at the time by the transmitter pointer 18.Thus it will be seen that no resetting or calibration is necessary afterthe integrity of the line is restored, and this proves that the systemor machine constitutingmy invention is able to take care of itselfautomatically not only while the line is inv perfect order but alsopromptly upon its restoration to good conditionsafter a suspension ofservice. V

I will offer a word or two with reference to the first adjustment of theparts at the first installation of the apparatus or at any future timewhen the receiver might be 'CllSCODllBGDGd for repairs, etc. We assumethat the arm 48 of the transmitter is directly behind the dialgraduation which represents the pressure in the tank. The line is openedby depressing the test-key, the pointer of the receiver will immediatelystart forward and work its way step by step com letely around thecircle. The point at whic li it makes the pause should be noted. For thesake of illustration suppose it is 19. This indicates that the machineis four points fast, for the pause should occurat 15, the lowest pointonthe scale, that is to say the zero point of this particular form ofscale which I am assuming is graduated from 15 to 29. Thehand istherefore set back four pointsby moving it on its shaft, on which it ismounted friction-tight like a clock hand. On testing again with thetest-key, it will be found that the pause occurs at the proper point,which is the lowest point, which shows that the machine is now setcorrectly and in unison with the transmitter.

I do not wish to be restricted to this method of adjusting or testingthe apparatus, and reserve the'liberty of'doing it in any The range ofthe transmitter described herein is 15 points or 1.5 units pressure,that is it can transmit pressure indications of 15 as 80, and then.

se ms units above the lowest unit to which the arm 48 and pointer '18 onshaft 7 may be set. This range may obviously be increased or decreasedto suit the particular requirements or range of pressure for which thetransmitter is used. The following relations must always be preserved inthe proportions of the various gears to each other. The gear 12 mustalways have half the number of teeth of the gear 8 no matter what therange is. Denoting the number of points or units in the range as as andthe number of times the circuit is opened at contacts 42 and 43 andobliterated or closed at contacts 49 and 50 as y, the number of teethrequired in gear 10 must be the number of teeth in gear eit- 2 her ofteeth in gear 63 must be such that it will make one complete revolutionwhen the The rack travels notch in disk 65 must be of such a length,that the contacts 67 and 68 will be closed while the disk 65 makes partof a revo- 9 divided by the quantity The numunits of pressure.

lution and open while it makes part of a cuit is obliterated and thepointer 77 of the receiver makes but one step at the pause in the timeit ordinarily consumes in making magnet 26 is to control the movement ofthe shaft ll by starting and "stopping it at the proper time, and thatthis magnet is rendered inoperative or operative by the position of thedisk 65 having notch 66 receiving the roller 69 carried by the spring 67While the roller 69 is in the notch 66, as shown in Fig. 5, the shaft 1]is at rest and locked, and obviously this is the normal position of theparts j'but whenever the disk is moved in one direction, as shown inFig. 6, or in the opposite direction, as shown in Fig. 7, as alreadyexplained, the magnet 26 is short-circuited and the shaft 11 instantlyreleased and allowed to revolve until the disk 65 gets back into itsnormal position again, which is accomplished automatically. In thusautomatically returning the disk 65 to its normal position through theagency of the control In the mechan- 18111 herein described, one openingof the onmagnet, the shaft'll'is caused to make in one make but one-halfa revolution to permit'the gear wheel 2 to drive the pinion'12 suffi-*ciently to cause the differential gear mechanism to move disk 65 in-aclockwise direc-' tion' through one-sixteenth of a revolution back intoits normal position. Suppose, however, that the disk 65 changes from theposition shown in 5 tothat shown-in Fig.

- 7, which takesplace when thepressurefalls one unit, thenthe shaft 11must revolve seven'and one-half timesinorderto transmit" to the disk 65aclockwise-movemerft through fifteen-sixteenthsof a revolution'which isthe amount necessary" to rotate the disk'to its normal position." Henceit -mus't beunder stood tht when thecontrol'magnet is energized it willstop the shaft '11 andprevent 'motion butwhen it is d emagnetized theshaft 1 1 is set free and allowedto revolve:

Suppose the" gas pressure increases or risesa unit, this increase isimmediately trans mitted by the rack 64 to thegear wheel-63,which-through the differential gearing operates shaft 59 and shifts thedisk 65i'nto'the' position shown in Fig. 6, lifting theroller 69* out ofthe notch "66, closing thecontact spring 67 against the screw 68-;thus-short" 'circuiting the magnet 26 and setting free the shaft 11, sothat the machine which has-been normally at rest is put into =motion,and the main line circuit is opened momentarilyand then closed. Thisoperation is performed once atthis'time, as the increase-in pressure isassumed to he'only onepoint." However-,

if the pressure "hadincreased two points or three points,theoperation-wouldberepeated in succession and the circuitopened'andclosed twice or three times, or as many times as the pressure11lCI'6EtS8S"IlI1ltS.

open and close the circuit fourteen times, for

themharacteristic of the mech-anis'nrwhich operates the disk 65 is'as wehave seen to always move it in a clockwise direction. In

case the pressure should decrease two units in succession, the circuitwould then- 'be opened and closed-thirteentimesyor if the pressuredecreases three units, the circuitopens and closes twelve timesyand-so011,313

all times the number of openingsand closings :1

of the circuit being equal to the number of units pressure decreasededucted from-1'5.

Moreover, if the circuit is opened and closedagain at anypoint on theline, as,-for instance,

at the test-key at the receiver, the machine immediately starts tooperate and opens and closes the circuit fourteen times in succession.

opposite of that of the magnet 26. Whereas WVhen the reverse actiontakes placeyhowever, and-thepressure decreasesa unit, themachin'eiwillof the pins 39 and34 so adjusted, and the pin-- '39 of suchailength that it will not passover pressing the keyymakes the-15operations already spoken of in describing the receiver.

The magnet35 acts in a manner the'dire'ct' the magnet 26 unlocks thecam-carrying shaft" 11 when it is demagnetized, the'magnet 35 unlocksthe said shaft when it is magnetized;

and when'its current is cut off, this magnet 35 causes-the "shaft 11 tostop, subject, how

ever, to the control which the c'ontrol'magnet exercises over shaft "11.The' magnet= 35 is,

therefore y'anemerge'ncy magnet, its principal I made a half revolution-and--preventits- "function beingtfostop the shaft 11 after it has 80"*further motion in the event of'the'supp'ly of' current' to--the=transmittingmachine being'cut off, which might be caused by themain circuit becoming broken, by-the battery'becoming inoperative, or bya short 5- 1 circuit occurring between-the transmitter andmitter'of'current. If any oneof these-contingencies should happen toarise and the control-ina'gnetshould in consequence become the'-battery," which would I deprive the transp .1 inoperative; the shaft 11being left free 'wouldw revolve indefinitely until" the weighthadrondown, and-this is what I-wish to avoid by the use of the emergencymagnet 35, and I dose-'- inthema-nner just explained, for the magnet A'35 when demagnetizedlocks the shaft-F11.

That is to say, when the same condition takesplace which destroysthefuncti'o'n of the con-" trol magnet and unlocksthe shaft 11, this"same condition enables the'emergency magnet to perform its'functionof-locking'the sh'aftll l and stopping its motion, so thatconsequently,- after it makes but one-half of a revolution,

should any oneof the contingencies men *tioned take'place; the controlmagnet will instantly unlock-shaft 11 which will start to P -rrevolve,but the action of the emergency "magnet in stopping the-shaft is sotimed -orregulated as previously explained that itis purposely delayedso that it is not possible for it to stop shaft 11 until after'it hasmade -onehalf of a revolution. This delay-is accomplished'by having therelative positions the-pin 34 and-operate to loclc'the'latch '20 andstopthe shaft 11, until after-the latter has made a halfrevolution.

length that whilethe armature 36 is attract-- ed to themagnet-35ftheleftend of this'pin 39 will reach almost to the pin 34 so that if thearmature 36 hereleasedthe spring 40. =would draw the-pin39 over the pin34 before- *it had a chance to lift and 'unloc-ktlie shaftl- 1 Ifsuchwere the case, should the-circuit be opened outside thetransmitterythe armatrol'magnet-26 and-allow the leftend'of latch Thismaybe. cunder'stood better by assuming for the sake P of illustration,that the pin 39 is of'such' a ture 27 would instantlyr'ecede'fromthe-con- 20, if free, to fall and unlock shaft 11; but thiswould not happen because the instant the circuit was opened, armature 36would next change in pressure takes place.

recede from magnet 35 and cause pin 39 to advance over pin 34, thuspreventing the left end of the latch 20 from falling and unlocking shaft11. tween the pins 39 and 34, I am able when. the armature 36 isattracted to the magnet 35, to delay the action of pin 39 and stop theshaft 11 by passing pin 39 over pin'34, and it is found 1n experiencenecessary to have this distance between the two pins so adjusted that ifthe circuit should be opened, for i11- stance by depressing the test-key80 at the receiver station, the pin 39 will not act to stop the shaft 11by advancing over the pin 34, until after the shaft 11 has made one-halfof a revolution.

In the operation of my improved machine for transmitting pressureindications, it is to be noted that it is normally at rest except when achange in pressure takes place, at which time the shaft 1 1 is released,which re- 25 sults in the transmission of the proper impulse to thereceiver end, after which the shaft 11 is stopped and held at rest untilthe mally at rest with the shaft 11 locked, the

cam 17 must be so placed onshaft 1 1 that the knob 47 of the contactspring 42 will rest opposite to the low part b of the periphery of thecam and not in contact with either of its high parts a, wherefore thespring 42 will keep its contact 45 against the contact 46 of spring 43,and thus preserve the continuity of the circuit at that point, while thebeginning of the adjacent high parta of the cam 41 must be close to thesaid knob 47 so thatthe instant after shaft 11 is unlocked andstarts torotate, the circuit will be opened at springs 42 and 43, and willbeclosed again after shaft 1.1 has made one-quarter of a revolution. Atthis point of the revolution of the shaft 11, the latch pin 24 has nowlifted sufficiently high to allow the pin 30 to advance under it shouldmagnet 26 become operative,

which explains the necessity for having the circuit closed at springs 42and 43 after the shaft 11 has made a quarter revolution. We have alreadyseen that if the main circuit should become inoperative, the magnet 35acts to hold the shaft 11 after it has made one half revolution and themachine is left at rest and ready to respond to the effect of thecurrent when the integrity of the circuit has been restored when it willimmediately start in mo- By adjusting the distance be.

It is therefore necessary that the tion until the disk 65 reaches thenormal position. Should the circuit become inopera tive again before thenotchin disk 65 reaches the normal position, the magnet 35 would actagain to sto and hold shaft 11 so that the resultant e ect of suchinterruptions of the main circuit would be merely to delay thetransmission of the proper signals and the operations of the receivermagnet would in all cases be such as to keep the pointer 78 in unisonwith the pointer 18 on shaft 7 when the circuit is in its normalcondition. It is therefore evident that the magnet 35 besides acting inan emergency capacity to prevent the transmitter running down whendeprived of current alsoacts to preserve the synchronism existingbetween the transmitter and receiver, even after temporary absences ofcurrent and variations of pressure at the transmitter during suchinterruptions which is an important and valuable feature of theoperation of the machine.

Very many modifications may be made in the invention without departingfrom the same. I have shown the shaft 3 as projecting through the frame1 and provided with a screw-threaded end for the application of awinding key wherewith to wind up the drum and its weight, but this maybemodified and other winding devices employed. In fact, I reserve theliberty of varying the combination and relation of parts, and changingthe same in form and function, without transcending the limits of myprotection by Let ters Patent.

I Having thus described my invention what I claim as new and desire tosecure by Letters-Patent, is

' 1. In a gage or indicator, the combination of a single electricalcircuit, normally closed during the interval between changes orvariations of the thing to be indicated, and having an impressedelectromotive force of unchanging polarity, said electromotive force andthe resistance being normally constant and invariable, a' transmittingmeans operated by changes in the thing to be indicated, a receivingmeans operated by impulses from the transmitter and synchronouslytherewith, said receiving me ans having visual indicating means,together with means whereby the indicating means has amyerificationpause.

2. In a gage or indicator for indicating pressures at a distance, thecombination of a single electrical circuit, normally closed and having acurrent of unchanging polarity, a

transmitting device wherein the circuit is opened and closed by pressurefluctuations, a

receiving device 0 erated by impulses from the transmitter ansynchronously therewith,

said receiving device being provided with indicating means, togetherwith means whereby the indicating means has a verification pause.

3. In a gage or indicatorfor indicating pressures, the combination of anelectrical.

cating means and operating synchronously with the transmitter, togetherwith means whereby the indicator has a verification pause.

4. In a gage or indicator, the combination of an electrical circuit, atransmitting device in said circuit actuated by pressure fluctuations toopen and close the latter, a receiver device having means for indicatingthese changes of pressure. and operating synchronously with thetransmitter, together with means whereby the indicator delays itsmovement at a certain point to provide an accuracy test.

5. In a gage or indicator, the combination of a single electricalcircuit normally closed and having a current of unchanging polarity, atransmitter operated by changes in the thing to be indicated, areceiveroperated by impulses from the transmitter, and means whereby theposition of one impulse in a series of impulses is made variable withrespect to the others.

6. In a mechanism for transmitting indications, the combination with areceiver, of a transmitter in the circuit therewith consistingessentially of an electromagnet, a camcarrying shaft, a latchcontrolling the shaft and itself controlled by the magnet, an operatingdisk, and means actuated thereby for shortcircuiting the magnet, meanswhereby variations in the pressure of fluid or thing under observationare transmitted to the disk, and means for restoring the disk to its,

normal condition and simultaneously actuating the cam-carrying shaft,and means operated by said shaft to open and close the circuit atintervals, substantially as described.

7. In a mechanismfor transmitting changes of pressure and the like, thecombination with an indicator, of a transmitting device for sendingelectrical impulses to the indicator in correspondence with fluctuationsof pressure and the like, said transmitter consisting essentially of anelectro-magnet, a cam-carrying shaft controlled thereby and havingthereon a circuit-breaking cam, a latch-releasing cam and a detent, a.disk for controlling the magnet circuit, means whereby changes ofpressure move the disk in one 1 direction or the other, and means 'forrestoring the disk to its normal position by revolving it always in thesame direction.

8,. In a mechanism for transmitting electrical impulses to indicatechanges of press sure or the like, the combination of a transmltter ,anda receiver 1n the same circuit, said receiver being distant from thetransmitter and indicating changes of pressure as received from theoperation of the transmitter, and said transmitter consistingessenshaft, controlled by the magnet, means for like magnetizeand-demagnetize the magnet, means for restoring the latter means to anormal condition after each change of pressure, and. means for actuatingthe cam-carrying shaft, the same including means for neutralizing one ofthe breaks in the circuit so thata longer interval occurs at one point.

9. In a gage for indicating pressures, the

atthe transmitter, of a transmitter in the ciran electro-magnet,acam-carrying shaft controlled thereby, means for performing said.control, said shaft itself controlling the opening and. closing of thecircuit, a disk and means actuated thereby operating tomagnetize anddemagnetize the magnet, means whereby said disk is controlled by thepressure fluctuations, and a mechanism including -a differential gearingfor restoring the disk to its normal position after each movement,together with a clockwork mechanism.

10. In a gage for indicating changes of pressure, the combination with areceiver which indicates the changes transmitted, of a transmitterconsisting essentially of an electro-magnet adapted to be energized anddemagnetized, mechanism controlled by the magnet for opening and closingthe circuit, a disk together with contacts controlled there by forshort-circuiting the magnet, means whereby the pressure fluctuationsshift the: disk in one direction or the other, and means for restoringthe disk to its normal position consisting essentially. of adifferential gearing, and a clockwork mechanism.

11. In a gage for indicating pressures, the combination of'a receiverwhich indicates the changes of pressure, and a transmitter whosemechanism includes a disk movablein one.

direction or the other by changes of pressure but always revolving inthe same direction while being restored to the normal, means forperforming said movement of the disk, an

electro-magnet whose circuit is controlled by i the disk, a cam-carryingshaft controlled by g the magnet and itself controlling the breaking andclosing of the circuit, and a latch de- 1 vice arranged in conjunctionwith the camcarrying shaft to regulate the movement of the same.

12. In a gage for indicating fluid or liquid pressures at a distance,the combination with a single electrical circuit, normally closed duringthe interval between changes or variations of the thing to be indicated,and having animpressed electromotive force of unchanging polarity, saidelectromotive force 1 and the resistance being normally constant tiallyof an electro-magnet, a cam-carrying.

combination with a receiver which indicates. the reproductions of thechanges taking place.

cuit with the receiver consisting essentially of.

performing said control, said shaft itself controlling the breaking ofthe circuit, means. whereby the fluctuations of pressure or the,

' and invariable, a transmitter which gives electrical impulses, saidtransmitter being operated by changes in the thing to be indicated, anda receiver operated by the 1m- 7 pulses from the transmitter, saidreceiver having a pointer and a scale.

13. In a gage for indicating pressures and the like at a distance, thecombination of an electrical circuit including a transmittercontrol-magnet and a receiver-magnet, a disk which is moved backward orforward in correspondencewith the changes to be indicated, meansactuated by the disk, said disk and means actuated thereby, controllingthe circuit of the transmitter controlmagnet, means for restoring thedisk to normal after its operation, a device whereby the impulsestransmitted to the receiver-magnet are interpreted to the attendant,means controlled by the transmitter control-magnet for opening andclosing the circuit for a succession of intervals, and means whereby oneof these openings is neutralized so as to lengthen one interval.

14. In a mechanism for indicating changes of pressure or the like at adistance, the combination of a main line and a receiver at the farend,of a transmitting mechanism comprising essentially anelectro-magnet, a camcarrying shaft, means operated by said shaft foropening and closing the circuit, a disk ac tuated by the changes ofpressure, means actuated by the disk for controlling the energizing ofthe magnet, and an emergency magnet whose function is to lock thecamcarrying shaft. at times, and means cooperating with the emergencymagnet in the performance of its function.

' 15. The combination of an electric line, a receiver at one endthereof, and a transmitter consisting essentially of a control magnetand its armature, a latch operating in conjunction with the armature, acam-carrying shaft having thereon a latch-lifting cam, acircuit-breaking cam, and a detent, contacts in the electrical circuitadapted to be opened by the circuit-breaking cam, a disk operated by thechanges of the thing to be indicated and communicating its movementelectrically to the magnet so as to control the energizing of thelatter, and a suitable mechanism for running the ca1n-carrying shaft andthe disk, and a pair of contacts arranged to be closed by the operationof the mechanism simultaneously with one of the openings of the circuitby the circuit-breaking cam so as to destroy the efiectof one of theopenings and provide a longer interval.

16. In a gage or indicator, the combination with a receiver whichindicates the im pulses transmitted, of a transmitting mechanismconsisting essentially of a controlmagnet, means operated thereby foropening and closing the circuit a series of times, a disk controllingthe circuit through the magnet and operated by the pressure fiuctuations, an actuating mechanism for the disk and the circuit-breakingmeans controlled by the magnet, and means for neutralizing one of theopenings in the circuit to provide a longer interval at one point.

17. In a gage or indicator, the combination with a main line, a receiverwhich indi cates the impulses transmitted, of a trans mitting mechanismconsisting essentially of a control-magnet, means operated thereby foropening and closing the circuit a series of times, a disk, and meansactuated thereby controlling the circuit through the magnet and operatedby the pressure fluctuations, an actuating mechanism for the disk andthe circuit-breaking means controlled by the magnet. said actuatingmechanism including differential gearing, means for neutralizing one ofthe openings in the circuit to provide a longer interval at one point,and an emergency magnet provided with locking means for rendering thecircuit-breaking means temporarily inoperative.

18. In a gage or indicator, the combination with a receiver having apointer, of a transmitter for sending impulses to the receive, saidtransmitter consisting essentially of a control-magnet, circuit-breakingmeans controlled thereby, a disk controlling the circuit through themagnet, means whereby the pressure fluctuations actuate the disk, adriving mechanism for revolving said disk and restoring it to thenormal, the latter revolution being always in the same direction, andsaid driving mechanism running the circuit-breaking mechanism and beingprovided with means for neutralizing one of the breaks of the circuit, adial and its pointer arranged to be operated b the driving mechanismsynchronously wit the operation of the receiver pointer, and an emerency magnet for controlling the circuit-brea g means and stopping itwhen the line is broken or the battery out of order.

19. In a gage or indicator for showing changes of pressure of gas orother fluid or liquid, the combination with a receiver having anindicator, of means for transmitting impulses to the receivercorrespondingly with the following fluctuations of pressure, said meansconsisting of a weight-driven gearing, a control-magnet, an armaturetherefor, an arm "for which the said armature serves as a latch, acam-carrying shaft and means actuated thereby arranged to open and closethe circuit, a disk adapted to shift in one direction or the other bythe fluctuations of pressure, means for'shifting the disk, connectionsbetween the disk and the drive gearing consist- .ing essentially of adifferential earing for re-

